Two PIDs

A parent and a child want to confirm the link between them: each one prints the PID of the other. The child gets the parent's PID via getppid(), while the parent receives the child's PID directly from fork()'s return value.

Fork returns:

• 0 to the child
• the child's PID to the parent

The child prints first, and the parent waits with wait(NULL) before printing its own line. That's how we guarantee the order.

Input

• No input.

Output

• Line 1 (from the child): Child: my parent is X
• Line 2 (from the parent): Parent: my child is Y

The child always prints first, because the parent waits for the child to finish.

Example

The PIDs differ on each run; what matters is the relationship between them.

Output:
Child: my parent is 42
Parent: my child is 43

Use fork(), getpid(), getppid() from unistd.h and wait(NULL) from sys/wait.h.